A few days ago I was poking around on the internet, and an amazing youtube video told me how to play a GameBoy Advance game on any system legally. This includes the NES, the Sega Genesis, and even the Atari!
You will need:
•The system you plan on playing it on
•A Gameboy Advance/SP/DS/DS Lite
•A Gameboy Advance cartridge

Step 1: Gather all of the above in the same room at the same time. You could gather them all at different times, or in different places, but then it wouldn't work.

Step 2: Put the GAMEBOY Advance cartridge inside your GBA/SP/DS/DS Lite. This generally involves minimal hand-eye coordination; just enough to aim the cartridge into the correct slot. Then apply just enough force to press it in.

Step 3: Place the System with the cartridge on the system you wat to play on. This is the easiest part, seeing as to how gravity does half of the work. If you're in space, you don't need to worry, tape usually does the trick.

Step 4: Turn on the GBA/SP/DS/DS Lite. On every single on of them, there's a switch on the edge of the device, except for the botton on the DS. Also, be sure that the battery or batteries have power in them. It's no good to have a dead battery.

Step 5: Play the GBA Game on your system of choice. There's really nothing to it, except don't take it off or you're no longer playing it on the device of choice.

I hope this helped all of you Gameboy Advance fanatics out there. Have a happy Valentines Day! Or if you're single (most of you), have a happy 50% Off Candy Day afterwards!
TeeHee!